// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic OPP OF helpers
 *
 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
 *    Nishanth Menon
 *    Romit Dasgupta
 *    Kevin Hilman
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/of_device.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/energy_model.h>

#include "opp.h"

#define PHANDLE_MOD_VALUE 2
#define PHANDLE_DIV_VALUE 2
#define REGULATOR_COUNT_MUL 3
#define NUM_RECORD_MOD_VALUE 2
#define FREQ_MUL 1000

/*
 * Returns opp descriptor node for a device node, caller must
 * do of_node_put().
 */
static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np, int index)
{
    /* "operating-points-v2" can be an array for power domain providers */
    return of_parse_phandle(np, "operating-points-v2", index);
}

/* Returns opp descriptor node for a device, caller must do of_node_put() */
struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
{
    return _opp_of_get_opp_desc_node(dev->of_node, 0);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);

struct opp_table *_managed_opp(struct device *dev, int index)
{
    struct opp_table *opp_table, *managed_table = NULL;
    struct device_node *np;

    np = _opp_of_get_opp_desc_node(dev->of_node, index);
    if (!np) {
        return NULL;
    }

    list_for_each_entry(opp_table, &opp_tables, node)
    {
        if (opp_table->np == np) {
            /*
             * Multiple devices can point to the same OPP table and
             * so will have same node-pointer, np.
             *
             * But the OPPs will be considered as shared only if the
             * OPP table contains a "opp-shared" property.
             */
            if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
                _get_opp_table_kref(opp_table);
                managed_table = opp_table;
            }

            break;
        }
    }

    of_node_put(np);

    return managed_table;
}

/* The caller must call dev_pm_opp_put() after the OPP is used */
static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table, struct device_node *opp_np)
{
    struct dev_pm_opp *opp;

    mutex_lock(&opp_table->lock);

    list_for_each_entry(opp, &opp_table->opp_list, node)
    {
        if (opp->np == opp_np) {
            dev_pm_opp_get(opp);
            mutex_unlock(&opp_table->lock);
            return opp;
        }
    }

    mutex_unlock(&opp_table->lock);

    return NULL;
}

static struct device_node *of_parse_required_opp(struct device_node *np, int index)
{
    return of_parse_phandle(np, "required-opps", index);
}

/* The caller must call dev_pm_opp_put_opp_table() after the table is used */
static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
{
    struct opp_table *opp_table;
    struct device_node *opp_table_np;

    lockdep_assert_held(&opp_table_lock);

    opp_table_np = of_get_parent(opp_np);
    if (!opp_table_np) {
        goto err;
    }

    /* It is safe to put the node now as all we need now is its address */
    of_node_put(opp_table_np);

    list_for_each_entry(opp_table, &opp_tables, node)
    {
        if (opp_table_np == opp_table->np) {
            _get_opp_table_kref(opp_table);
            return opp_table;
        }
    }

err:
    return ERR_PTR(-ENODEV);
}

/* Free resources previously acquired by _opp_table_alloc_required_tables() */
static void _opp_table_free_required_tables(struct opp_table *opp_table)
{
    struct opp_table **required_opp_tables = opp_table->required_opp_tables;
    int i;

    if (!required_opp_tables) {
        return;
    }

    for (i = 0; i < opp_table->required_opp_count; i++) {
        if (IS_ERR_OR_NULL(required_opp_tables[i])) {
            break;
        }

        dev_pm_opp_put_opp_table(required_opp_tables[i]);
    }

    kfree(required_opp_tables);

    opp_table->required_opp_count = 0;
    opp_table->required_opp_tables = NULL;
}

/*
 * Populate all devices and opp tables which are part of "required-opps" list.
 * Checking only the first OPP node should be enough.
 */
static void _opp_table_alloc_required_tables(struct opp_table *opp_table, struct device *dev,
                                             struct device_node *opp_np)
{
    struct opp_table **required_opp_tables;
    struct device_node *required_np, *np;
    int count, i;

    /* Traversing the first OPP node is all we need */
    np = of_get_next_available_child(opp_np, NULL);
    if (!np) {
        dev_err(dev, "Empty OPP table\n");
        return;
    }

    count = of_count_phandle_with_args(np, "required-opps", NULL);
    if (!count) {
        goto put_np;
    }

    required_opp_tables = kcalloc(count, sizeof(*required_opp_tables), GFP_KERNEL);
    if (!required_opp_tables) {
        goto put_np;
    }

    opp_table->required_opp_tables = required_opp_tables;
    opp_table->required_opp_count = count;

    for (i = 0; i < count; i++) {
        required_np = of_parse_required_opp(np, i);
        if (!required_np) {
            goto free_required_tables;
        }

        required_opp_tables[i] = _find_table_of_opp_np(required_np);
        of_node_put(required_np);

        if (IS_ERR(required_opp_tables[i])) {
            goto free_required_tables;
        }

        /*
         * We only support genpd's OPPs in the "required-opps" for now,
         * as we don't know how much about other cases. Error out if the
         * required OPP doesn't belong to a genpd.
         */
        if (!required_opp_tables[i]->is_genpd) {
            dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n", required_np);
            goto free_required_tables;
        }
    }

    goto put_np;

free_required_tables:
    _opp_table_free_required_tables(opp_table);
put_np:
    of_node_put(np);
}

void _of_init_opp_table(struct opp_table *opp_table, struct device *dev, int index)
{
    struct device_node *np, *opp_np;
    u32 val;

    /*
     * Only required for backward compatibility with v1 bindings, but isn't
     * harmful for other cases. And so we do it unconditionally.
     */
    np = of_node_get(dev->of_node);
    if (!np) {
        return;
    }

    if (!of_property_read_u32(np, "clock-latency", &val)) {
        opp_table->clock_latency_ns_max = val;
    }
    of_property_read_u32(np, "voltage-tolerance", &opp_table->voltage_tolerance_v1);

    if (of_find_property(np, "#power-domain-cells", NULL)) {
        opp_table->is_genpd = true;
    }

    /* Get OPP table node */
    opp_np = _opp_of_get_opp_desc_node(np, index);
    of_node_put(np);

    if (!opp_np) {
        return;
    }

    if (of_property_read_bool(opp_np, "opp-shared")) {
        opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
    } else {
        opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
    }

    opp_table->np = opp_np;

    _opp_table_alloc_required_tables(opp_table, dev, opp_np);
    of_node_put(opp_np);
}

void _of_clear_opp_table(struct opp_table *opp_table)
{
    _opp_table_free_required_tables(opp_table);
}

/*
 * Release all resources previously acquired with a call to
 * _of_opp_alloc_required_opps().
 */
void _of_opp_free_required_opps(struct opp_table *opp_table, struct dev_pm_opp *opp)
{
    struct dev_pm_opp **required_opps = opp->required_opps;
    int i;

    if (!required_opps) {
        return;
    }

    for (i = 0; i < opp_table->required_opp_count; i++) {
        if (!required_opps[i]) {
            break;
        }

        /* Put the reference back */
        dev_pm_opp_put(required_opps[i]);
    }

    kfree(required_opps);
    opp->required_opps = NULL;
}

/* Populate all required OPPs which are part of "required-opps" list */
static int _of_opp_alloc_required_opps(struct opp_table *opp_table, struct dev_pm_opp *opp)
{
    struct dev_pm_opp **required_opps;
    struct opp_table *required_table;
    struct device_node *np;
    int i, ret, count = opp_table->required_opp_count;

    if (!count) {
        return 0;
    }

    required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
    if (!required_opps) {
        return -ENOMEM;
    }

    opp->required_opps = required_opps;

    for (i = 0; i < count; i++) {
        required_table = opp_table->required_opp_tables[i];

        np = of_parse_required_opp(opp->np, i);
        if (unlikely(!np)) {
            ret = -ENODEV;
            goto free_required_opps;
        }

        required_opps[i] = _find_opp_of_np(required_table, np);
        of_node_put(np);

        if (!required_opps[i]) {
            pr_err("%s: Unable to find required OPP node: %pOF (%d)\n", __func__, opp->np, i);
            ret = -ENODEV;
            goto free_required_opps;
        }
    }

    return 0;

free_required_opps:
    _of_opp_free_required_opps(opp_table, opp);

    return ret;
}

static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
{
    struct device_node *np, *opp_np;
    struct property *prop;

    if (!opp_table) {
        np = of_node_get(dev->of_node);
        if (!np) {
            return -ENODEV;
        }
        opp_np = _opp_of_get_opp_desc_node(np, 0);
        of_node_put(np);
    } else {
        opp_np = of_node_get(opp_table->np);
    }
    /* Lets not fail in case we are parsing opp-v1 bindings */
    if (!opp_np) {
        return 0;
    }
    /* Checking only first OPP is sufficient */
    np = of_get_next_available_child(opp_np, NULL);
    of_node_put(opp_np);
    if (!np) {
        dev_err(dev, "OPP table empty\n");
        return -EINVAL;
    }
    prop = of_find_property(np, "opp-peak-kBps", NULL);
    of_node_put(np);
    if (!prop || !prop->length) {
        return 0;
    }
    return 1;
}

int dev_pm_opp_of_find_icc_paths(struct device *dev, struct opp_table *opp_table)
{
    struct device_node *np;
    int ret, i, count, num_paths;
    struct icc_path **paths;

    ret = _bandwidth_supported(dev, opp_table);
    if (ret <= 0) {
        return ret;
    }

    ret = 0;

    np = of_node_get(dev->of_node);
    if (!np) {
        return 0;
    }

    count = of_count_phandle_with_args(np, "interconnects", "#interconnect-cells");
    of_node_put(np);
    if (count < 0) {
        return 0;
    }

    /* two phandles when #interconnect-cells = <1> */
    if (count % PHANDLE_MOD_VALUE) {
        dev_err(dev, "%s: Invalid interconnects values\n", __func__);
        return -EINVAL;
    }

    num_paths = count / PHANDLE_DIV_VALUE;
    paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
    if (!paths) {
        return -ENOMEM;
    }

    for (i = 0; i < num_paths; i++) {
        paths[i] = of_icc_get_by_index(dev, i);
        if (IS_ERR(paths[i])) {
            ret = PTR_ERR(paths[i]);
            if (ret != -EPROBE_DEFER) {
                dev_err(dev, "%s: Unable to get path%d: %d\n", __func__, i, ret);
            }
            goto err;
        }
    }

    if (opp_table) {
        opp_table->paths = paths;
        opp_table->path_count = num_paths;
        return 0;
    }

err:
    while (i--) {
        icc_put(paths[i]);
    }

    kfree(paths);

    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);

static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table, struct device_node *np)
{
    unsigned int levels = opp_table->supported_hw_count;
    int count, versions, ret, i, j;
    u32 val;

    if (!opp_table->supported_hw) {
        /*
         * In the case that no supported_hw has been set by the
         * platform but there is an opp-supported-hw value set for
         * an OPP then the OPP should not be enabled as there is
         * no way to see if the hardware supports it.
         */
        if (of_find_property(np, "opp-supported-hw", NULL)) {
            return false;
        } else {
            return true;
        }
    }

    count = of_property_count_u32_elems(np, "opp-supported-hw");
    if (count <= 0 || count % levels) {
        dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n", __func__, count);
        return false;
    }

    versions = count / levels;

    /* All levels in at least one of the versions should match */
    for (i = 0; i < versions; i++) {
        bool supported = true;

        for (j = 0; j < levels; j++) {
            ret = of_property_read_u32_index(np, "opp-supported-hw", i * levels + j, &val);
            if (ret) {
                dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n", __func__,
                         i * levels + j, ret);
                return false;
            }

            /* Check if the level is supported */
            if (!(val & opp_table->supported_hw[j])) {
                supported = false;
                break;
            }
        }

        if (supported) {
            return true;
        }
    }

    return false;
}

static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev, struct opp_table *opp_table)
{
    u32 *microvolt, *microamp = NULL;
    int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
    struct property *prop = NULL;
    char name[NAME_MAX];

    /* Search for "opp-microvolt-<name>" */
    if (opp_table->prop_name) {
        snprintf(name, sizeof(name), "opp-microvolt-%s", opp_table->prop_name);
        prop = of_find_property(opp->np, name, NULL);
    }

    if (!prop) {
        /* Search for "opp-microvolt" */
        sprintf(name, "opp-microvolt");
        prop = of_find_property(opp->np, name, NULL);
        /* Missing property isn't a problem, but an invalid entry is */
        if (!prop) {
            if (unlikely(supplies == -1)) {
                /* Initialize regulator_count */
                opp_table->regulator_count = 0;
                return 0;
            }

            if (!supplies) {
                return 0;
            }

            dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n", __func__);
            return -EINVAL;
        }
    }

    if (unlikely(supplies == -1)) {
        /* Initialize regulator_count */
        supplies = opp_table->regulator_count = 1;
    } else if (unlikely(!supplies)) {
        dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
        return -EINVAL;
    }

    vcount = of_property_count_u32_elems(opp->np, name);
    if (vcount < 0) {
        dev_err(dev, "%s: Invalid %s property (%d)\n", __func__, name, vcount);
        return vcount;
    }

    /* There can be one or three elements per supply */
    if (vcount != supplies && vcount != supplies * REGULATOR_COUNT_MUL) {
        dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n", __func__, name, vcount,
                supplies);
        return -EINVAL;
    }

    microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
    if (!microvolt) {
        return -ENOMEM;
    }

    ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
    if (ret) {
        dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
        ret = -EINVAL;
        goto free_microvolt;
    }

    /* Search for "opp-microamp-<name>" */
    prop = NULL;
    if (opp_table->prop_name) {
        snprintf(name, sizeof(name), "opp-microamp-%s", opp_table->prop_name);
        prop = of_find_property(opp->np, name, NULL);
    }

    if (!prop) {
        /* Search for "opp-microamp" */
        sprintf(name, "opp-microamp");
        prop = of_find_property(opp->np, name, NULL);
    }

    if (prop) {
        icount = of_property_count_u32_elems(opp->np, name);
        if (icount < 0) {
            dev_err(dev, "%s: Invalid %s property (%d)\n", __func__, name, icount);
            ret = icount;
            goto free_microvolt;
        }

        if (icount != supplies) {
            dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n", __func__, name,
                    icount, supplies);
            ret = -EINVAL;
            goto free_microvolt;
        }

        microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
        if (!microamp) {
            ret = -EINVAL;
            goto free_microvolt;
        }

        ret = of_property_read_u32_array(opp->np, name, microamp, icount);
        if (ret) {
            dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
            ret = -EINVAL;
            goto free_microamp;
        }
    }

    for (i = 0, j = 0; i < supplies; i++) {
        opp->supplies[i].u_volt = microvolt[j++];

        if (vcount == supplies) {
            opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
            opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
        } else {
            opp->supplies[i].u_volt_min = microvolt[j++];
            opp->supplies[i].u_volt_max = microvolt[j++];
        }

        if (microamp) {
            opp->supplies[i].u_amp = microamp[i];
        }
    }

free_microamp:
    kfree(microamp);
free_microvolt:
    kfree(microvolt);

    return ret;
}

/**
 * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 *                  entries
 * @dev:    device pointer used to lookup OPP table.
 *
 * Free OPPs created using static entries present in DT.
 */
void dev_pm_opp_of_remove_table(struct device *dev)
{
    dev_pm_opp_remove_table(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);

static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table, struct device_node *np, bool peak)
{
    const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
    struct property *prop;
    int i, count, ret;
    u32 *bw;

    prop = of_find_property(np, name, NULL);
    if (!prop) {
        return -ENODEV;
    }

    count = prop->length / sizeof(u32);
    if (table->path_count != count) {
        pr_err("%s: Mismatch between %s and paths (%d %d)\n", __func__, name, count, table->path_count);
        return -EINVAL;
    }

    bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
    if (!bw) {
        return -ENOMEM;
    }

    ret = of_property_read_u32_array(np, name, bw, count);
    if (ret) {
        pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
        goto out;
    }

    for (i = 0; i < count; i++) {
        if (peak) {
            new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
        } else {
            new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
        }
    }

out:
    kfree(bw);
    return ret;
}

static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table, struct device_node *np,
                         bool *rate_not_available)
{
    bool found = false;
    u64 rate;
    int ret;

    ret = of_property_read_u64(np, "opp-hz", &rate);
    if (!ret) {
        /*
         * Rate is defined as an unsigned long in clk API, and so
         * casting explicitly to its type. Must be fixed once rate is 64
         * bit guaranteed in clk API.
         */
        new_opp->rate = (unsigned long)rate;
        found = true;
    }
    *rate_not_available = !!ret;

    /*
     * Bandwidth consists of peak and average (optional) values:
     * opp-peak-kBps = <path1_value path2_value>;
     * opp-avg-kBps = <path1_value path2_value>;
     */
    ret = _read_bw(new_opp, table, np, true);
    if (!ret) {
        found = true;
        ret = _read_bw(new_opp, table, np, false);
    }

    /* The properties were found but we failed to parse them */
    if (ret && ret != -ENODEV) {
        return ret;
    }

    if (!of_property_read_u32(np, "opp-level", &new_opp->level)) {
        found = true;
    }

    if (found) {
        return 0;
    }

    return ret;
}

/**
 * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 * @opp_table:    OPP table
 * @dev:    device for which we do this operation
 * @np:        device node
 *
 * This function adds an opp definition to the opp table and returns status. The
 * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 * removed by dev_pm_opp_remove.
 *
 * Return
 * Valid OPP pointer:
 *        On success
 * NULL:
 *        Duplicate OPPs (both freq and volt are same) and opp->available
 *        OR if the OPP is not supported by hardware.
 * ERR_PTR(-EEXIST):
 *        Freq are same and volt are different OR
 *        Duplicate OPPs (both freq and volt are same) and !opp->available
 * ERR_PTR(-ENOMEM):
 *        Memory allocation failure
 * ERR_PTR(-EINVAL):
 *        Failed parsing the OPP node
 */
static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table, struct device *dev, struct device_node *np)
{
    struct dev_pm_opp *new_opp;
    u32 val;
    int ret;
    bool rate_not_available = false;

    new_opp = _opp_allocate(opp_table);
    if (!new_opp) {
        return ERR_PTR(-ENOMEM);
    }

    ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
    if (ret < 0 && !opp_table->is_genpd) {
        dev_err(dev, "%s: opp key field not found\n", __func__);
        goto free_opp;
    }

    /* Check if the OPP supports hardware's hierarchy of versions or not */
    if (!_opp_is_supported(dev, opp_table, np)) {
        dev_dbg(dev, "OPP not supported by hardware: %lu\n", new_opp->rate);
        goto free_opp;
    }

    new_opp->turbo = of_property_read_bool(np, "turbo-mode");

    new_opp->np = np;
    new_opp->dynamic = false;
    new_opp->available = true;

    ret = _of_opp_alloc_required_opps(opp_table, new_opp);
    if (ret) {
        goto free_opp;
    }

    if (!of_property_read_u32(np, "clock-latency-ns", &val)) {
        new_opp->clock_latency_ns = val;
    }

    ret = opp_parse_supplies(new_opp, dev, opp_table);
    if (ret) {
        goto free_required_opps;
    }

    if (opp_table->is_genpd) {
        new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
    }

    ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
    if (ret) {
        /* Don't return error for duplicate OPPs */
        if (ret == -EBUSY) {
            ret = 0;
        }
        goto free_required_opps;
    }

    /* OPP to select on device suspend */
    if (of_property_read_bool(np, "opp-suspend")) {
        if (opp_table->suspend_opp) {
            /* Pick the OPP with higher rate as suspend OPP */
            if (new_opp->rate > opp_table->suspend_opp->rate) {
                opp_table->suspend_opp->suspend = false;
                new_opp->suspend = true;
                opp_table->suspend_opp = new_opp;
            }
        } else {
            new_opp->suspend = true;
            opp_table->suspend_opp = new_opp;
        }
    }

    if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max) {
        opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
    }

    pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n", __func__, new_opp->turbo, new_opp->rate,
             new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min, new_opp->supplies[0].u_volt_max,
             new_opp->clock_latency_ns);

    /*
     * Notify the changes in the availability of the operable
     * frequency/voltage list.
     */
    blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
    return new_opp;

free_required_opps:
    _of_opp_free_required_opps(opp_table, new_opp);
free_opp:
    _opp_free(new_opp);

    return ret ? ERR_PTR(ret) : NULL;
}

/* Initializes OPP tables based on new bindings */
static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
{
    struct device_node *np;
    int ret, count = 0;
    struct dev_pm_opp *opp;

    /* OPP table is already initialized for the device */
    mutex_lock(&opp_table->lock);
    if (opp_table->parsed_static_opps) {
        opp_table->parsed_static_opps++;
        mutex_unlock(&opp_table->lock);
        return 0;
    }

    opp_table->parsed_static_opps = 1;
    mutex_unlock(&opp_table->lock);

    /* We have opp-table node now, iterate over it and add OPPs */
    for_each_available_child_of_node(opp_table->np, np)
    {
        opp = _opp_add_static_v2(opp_table, dev, np);
        if (IS_ERR(opp)) {
            ret = PTR_ERR(opp);
            dev_err(dev, "%s: Failed to add OPP, %d\n", __func__, ret);
            of_node_put(np);
            goto remove_static_opp;
        } else if (opp) {
            count++;
        }
    }

    /* There should be one or more OPPs defined */
    if (!count) {
        dev_err(dev, "%s: no supported OPPs", __func__);
        ret = -ENOENT;
        goto remove_static_opp;
    }

    list_for_each_entry(opp, &opp_table->opp_list, node)
    {
        /* Any non-zero performance state would enable the feature */
        if (opp->pstate) {
            opp_table->genpd_performance_state = true;
            break;
        }
    }

    return 0;

remove_static_opp:
    _opp_remove_all_static(opp_table);

    return ret;
}

/* Initializes OPP tables based on old-deprecated bindings */
static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
{
    const struct property *prop;
    const __be32 *val;
    int nr, ret = 0;

    mutex_lock(&opp_table->lock);
    if (opp_table->parsed_static_opps) {
        opp_table->parsed_static_opps++;
        mutex_unlock(&opp_table->lock);
        return 0;
    }

    opp_table->parsed_static_opps = 1;
    mutex_unlock(&opp_table->lock);

    prop = of_find_property(dev->of_node, "operating-points", NULL);
    if (!prop) {
        ret = -ENODEV;
        goto remove_static_opp;
    }
    if (!prop->value) {
        ret = -ENODATA;
        goto remove_static_opp;
    }

    /*
     * Each OPP is a set of tuples consisting of frequency and
     * voltage like <freq-kHz vol-uV>.
     */
    nr = prop->length / sizeof(u32);
    if (nr % NUM_RECORD_MOD_VALUE) {
        dev_err(dev, "%s: Invalid OPP table\n", __func__);
        ret = -EINVAL;
        goto remove_static_opp;
    }

    val = prop->value;
    while (nr) {
        unsigned long freq = be32_to_cpup(val++) * FREQ_MUL;
        unsigned long volt = be32_to_cpup(val++);

        ret = _opp_add_v1(opp_table, dev, freq, volt, false);
        if (ret) {
            dev_err(dev, "%s: Failed to add OPP %ld (%d)\n", __func__, freq, ret);
            goto remove_static_opp;
        }
        nr -= NUM_RECORD_MOD_VALUE;
    }

    return 0;

remove_static_opp:
    _opp_remove_all_static(opp_table);

    return ret;
}

/**
 * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 * @dev:    device pointer used to lookup OPP table.
 *
 * Register the initial OPP table with the OPP library for given device.
 *
 * Return:
 * 0        On success OR
 *        Duplicate OPPs (both freq and volt are same) and opp->available
 * -EEXIST    Freq are same and volt are different OR
 *        Duplicate OPPs (both freq and volt are same) and !opp->available
 * -ENOMEM    Memory allocation failure
 * -ENODEV    when 'operating-points' property is not found or is invalid data
 *        in device node.
 * -ENODATA    when empty 'operating-points' property is found
 * -EINVAL    when invalid entries are found in opp-v2 table
 */
int dev_pm_opp_of_add_table(struct device *dev)
{
    struct opp_table *opp_table;
    int ret;

    opp_table = dev_pm_opp_get_opp_table_indexed(dev, 0);
    if (IS_ERR(opp_table)) {
        return PTR_ERR(opp_table);
    }

    /*
     * OPPs have two version of bindings now. Also try the old (v1)
     * bindings for backward compatibility with older dtbs.
     */
    if (opp_table->np) {
        ret = _of_add_opp_table_v2(dev, opp_table);
    } else {
        ret = _of_add_opp_table_v1(dev, opp_table);
    }

    if (ret) {
        dev_pm_opp_put_opp_table(opp_table);
    }

    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);

/**
 * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
 * @dev:    device pointer used to lookup OPP table.
 * @index:    Index number.
 *
 * Register the initial OPP table with the OPP library for given device only
 * using the "operating-points-v2" property.
 *
 * Return:
 * 0        On success OR
 *        Duplicate OPPs (both freq and volt are same) and opp->available
 * -EEXIST    Freq are same and volt are different OR
 *        Duplicate OPPs (both freq and volt are same) and !opp->available
 * -ENOMEM    Memory allocation failure
 * -ENODEV    when 'operating-points' property is not found or is invalid data
 *        in device node.
 * -ENODATA    when empty 'operating-points' property is found
 * -EINVAL    when invalid entries are found in opp-v2 table
 */
int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
{
    struct opp_table *opp_table;
    int ret, count;

    if (index) {
        /*
         * If only one phandle is present, then the same OPP table
         * applies for all index requests.
         */
        count = of_count_phandle_with_args(dev->of_node, "operating-points-v2", NULL);
        if (count == 1) {
            index = 0;
        }
    }

    opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
    if (IS_ERR(opp_table)) {
        return PTR_ERR(opp_table);
    }

    ret = _of_add_opp_table_v2(dev, opp_table);
    if (ret) {
        dev_pm_opp_put_opp_table(opp_table);
    }

    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);

/* CPU device specific helpers */

/**
 * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
 * @cpumask:    cpumask for which OPP table needs to be removed
 *
 * This removes the OPP tables for CPUs present in the @cpumask.
 * This should be used only to remove static entries created from DT.
 */
void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
{
    _dev_pm_opp_cpumask_remove_table(cpumask, -1);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);

/**
 * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
 * @cpumask:    cpumask for which OPP table needs to be added.
 *
 * This adds the OPP tables for CPUs present in the @cpumask.
 */
int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
{
    struct device *cpu_dev;
    int cpu, ret;

    if (WARN_ON(cpumask_empty(cpumask))) {
        return -ENODEV;
    }

    for_each_cpu(cpu, cpumask)
    {
        cpu_dev = get_cpu_device(cpu);
        if (!cpu_dev) {
            pr_err("%s: failed to get cpu%d device\n", __func__, cpu);
            ret = -ENODEV;
            goto remove_table;
        }

        ret = dev_pm_opp_of_add_table(cpu_dev);
        if (ret) {
            /*
             * OPP may get registered dynamically, don't print error
             * message here.
             */
            pr_debug("%s: couldn't find opp table for cpu:%d, %d\n", __func__, cpu, ret);

            goto remove_table;
        }
    }

    return 0;

remove_table:
    /* Free all other OPPs */
    _dev_pm_opp_cpumask_remove_table(cpumask, cpu);

    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);

/*
 * Works only for OPP v2 bindings.
 *
 * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 */
/**
 * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 *                      @cpu_dev using operating-points-v2
 *                      bindings.
 *
 * @cpu_dev:    CPU device for which we do this operation
 * @cpumask:    cpumask to update with information of sharing CPUs
 *
 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 *
 * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 */
int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{
    struct device_node *np, *tmp_np, *cpu_np;
    int cpu, ret = 0;

    /* Get OPP descriptor node */
    np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
    if (!np) {
        dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
        return -ENOENT;
    }

    cpumask_set_cpu(cpu_dev->id, cpumask);

    /* OPPs are shared ? */
    if (!of_property_read_bool(np, "opp-shared")) {
        goto put_cpu_node;
    }

    for_each_possible_cpu(cpu)
    {
        if (cpu == cpu_dev->id) {
            continue;
        }

        cpu_np = of_cpu_device_node_get(cpu);
        if (!cpu_np) {
            dev_err(cpu_dev, "%s: failed to get cpu%d node\n", __func__, cpu);
            ret = -ENOENT;
            goto put_cpu_node;
        }

        /* Get OPP descriptor node */
        tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
        of_node_put(cpu_np);
        if (!tmp_np) {
            pr_err("%pOF: Couldn't find opp node\n", cpu_np);
            ret = -ENOENT;
            goto put_cpu_node;
        }

        /* CPUs are sharing opp node */
        if (np == tmp_np) {
            cpumask_set_cpu(cpu, cpumask);
        }

        of_node_put(tmp_np);
    }

put_cpu_node:
    of_node_put(np);
    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);

/**
 * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
 * @np: Node that contains the "required-opps" property.
 * @index: Index of the phandle to parse.
 *
 * Returns the performance state of the OPP pointed out by the "required-opps"
 * property at @index in @np.
 *
 * Return: Zero or positive performance state on success, otherwise negative
 * value on errors.
 */
int of_get_required_opp_performance_state(struct device_node *np, int index)
{
    struct dev_pm_opp *opp;
    struct device_node *required_np;
    struct opp_table *opp_table;
    int pstate = -EINVAL;

    required_np = of_parse_required_opp(np, index);
    if (!required_np) {
        return -ENODEV;
    }

    opp_table = _find_table_of_opp_np(required_np);
    if (IS_ERR(opp_table)) {
        pr_err("%s: Failed to find required OPP table %pOF: %ld\n", __func__, np, PTR_ERR(opp_table));
        goto put_required_np;
    }

    opp = _find_opp_of_np(opp_table, required_np);
    if (opp) {
        pstate = opp->pstate;
        dev_pm_opp_put(opp);
    }

    dev_pm_opp_put_opp_table(opp_table);

put_required_np:
    of_node_put(required_np);

    return pstate;
}
EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);

/**
 * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
 * @opp:    opp for which DT node has to be returned for
 *
 * Return: DT node corresponding to the opp, else 0 on success.
 *
 * The caller needs to put the node with of_node_put() after using it.
 */
struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
{
    if (IS_ERR_OR_NULL(opp)) {
        pr_err("%s: Invalid parameters\n", __func__);
        return NULL;
    }

    return of_node_get(opp->np);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);

/*
 * Callback function provided to the Energy Model framework upon registration.
 * This computes the power estimated by @dev at @kHz if it is the frequency
 * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
 * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
 * frequency and @mW to the associated power. The power is estimated as
 * P = C * V^2 * f with C being the device's capacitance and V and f
 * respectively the voltage and frequency of the OPP.
 *
 * Returns -EINVAL if the power calculation failed because of missing
 * parameters, 0 otherwise.
 */
static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz, struct device *dev)
{
    struct dev_pm_opp *opp;
    struct device_node *np;
    unsigned long mV, Hz;
    u32 cap;
    u64 tmp;
    int ret;

    np = of_node_get(dev->of_node);
    if (!np) {
        return -EINVAL;
    }

    ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
    of_node_put(np);
    if (ret) {
        return -EINVAL;
    }

    Hz = *kHz * 1000;
    opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
    if (IS_ERR(opp)) {
        return -EINVAL;
    }

    mV = dev_pm_opp_get_voltage(opp) / 1000;
    dev_pm_opp_put(opp);
    if (!mV) {
        return -EINVAL;
    }

    tmp = (u64)cap * mV * mV * (Hz / 1000000);
    do_div(tmp, 1000000000);

    *mW = (unsigned long)tmp;
    *kHz = Hz / 1000;

    return 0;
}

/**
 * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
 * @dev        : Device for which an Energy Model has to be registered
 * @cpus    : CPUs for which an Energy Model has to be registered. For
 *        other type of devices it should be set to NULL.
 *
 * This checks whether the "dynamic-power-coefficient" devicetree property has
 * been specified, and tries to register an Energy Model with it if it has.
 * Having this property means the voltages are known for OPPs and the EM
 * might be calculated.
 */
int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
{
    struct em_data_callback em_cb = EM_DATA_CB(_get_power);
    struct device_node *np;
    int ret, nr_opp;
    u32 cap;

    if (IS_ERR_OR_NULL(dev)) {
        ret = -EINVAL;
        goto failed;
    }

    nr_opp = dev_pm_opp_get_opp_count(dev);
    if (nr_opp <= 0) {
        ret = -EINVAL;
        goto failed;
    }

    np = of_node_get(dev->of_node);
    if (!np) {
        ret = -EINVAL;
        goto failed;
    }

    /*
     * Register an EM only if the 'dynamic-power-coefficient' property is
     * set in devicetree. It is assumed the voltage values are known if that
     * property is set since it is useless otherwise. If voltages are not
     * known, just let the EM registration fail with an error to alert the
     * user about the inconsistent configuration.
     */
    ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
    of_node_put(np);
    if (ret || !cap) {
        dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
        ret = -EINVAL;
        goto failed;
    }

    ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
    if (ret) {
        goto failed;
    }

    return 0;

failed:
    dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
    return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);
